JP2014155897A - Ionizing radiation curable film formation body production method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a production method of an ionizing radiation curable film formation body capable of forming, with high adhesion force, an ionizing radiation curable film on a substrate having low surface activity without using an adhesive agent or a primer.SOLUTION: A production method of an ionizing radiation curable film formation body comprises the steps of: applying an ionizing radiation curable composition to one surface of a substrate 1; drying the substrate 1; irradiating the substrate 1 with an electron beam from the other surface side of the substrate; and irradiating the substrate 1 with an ionization radiation from the one surface side of the substrate, and these steps are performed sequentially and continuously.

Description

  The present invention relates to a method for producing an ionizing radiation curable coating film formed on one surface of a plastic substrate.

  Conventionally, vinyl chloride resin (vinyl chloride) has been the mainstream as a base material for decorative sheets used for flooring and wallpaper, because of the advantages of printing and post-processing and cost. However, in recent years, PVC base materials have become a problem due to environmental problems and the like, and as an alternative, more environmentally-friendly olefin resin base materials such as polyethylene and polypropylene have been used.

  Furthermore, the decorative sheet is required to have high resistance and high function. For example, in addition to the design properties by printing or embossing applied on the base material, a protective layer represented by a hard coat or the like is provided. Is formed.

  In general, the protective layer as described above provides surface hardness and weather resistance, and many of them are composed of an electron beam curable resin or an ultraviolet curable resin as a protective layer on one surface of the substrate. An ionizing radiation curable coating film is formed.

  However, when the olefin resin substrate as described above is used, there is a problem as a practical level due to the lack of adhesion with the ionizing radiation curable coating film due to the low surface activity of the olefin resin substrate. is there.

  Therefore, in the case of using the olefin-based resin substrate as described above, it is generally known that an adhesive or a primer treatment is applied in order to improve the adhesion with the ionizing radiation curable coating film. Yes.

  For example, in order to improve the resistance of the base material, a primer is applied to the base material, an ultraviolet curable paint is applied thereon, a film is laminated thereon, and then cured by irradiating with ultraviolet light, thereby unnecessary film. There has been proposed a method of removing (Patent Document 1).

  However, if a primer or an adhesive is used as described above in order to improve the adhesion between the base material and the ionizing radiation curable coating film, the number of steps increases, resulting in a problem of reduced productivity and high cost.

JP-A-62-61677

  The present invention provides an ionizing radiation curable coating that can form an ionizing radiation curable coating film on a substrate having low surface activity with high adhesion without using an adhesive or a primer. It aims at providing the manufacturing method of a film formation body.

The invention of claim 1 according to the present invention is a step of applying an ionizing radiation curable composition to one surface of a substrate, a step of drying, and a step of irradiating an electron beam from the other surface side of the substrate. And a step of irradiating ionizing radiation from one surface side of the base material sequentially and successively.

  Further, the invention of claim 2 is directed to a drying furnace and the ionizing radiation provided in the drying step by an electron beam irradiation apparatus that irradiates the electron beam in the step of irradiating the electron beam from the other surface side of the substrate. It is installed between the ionizing radiation irradiation apparatuses with which the process of irradiating was carried out, It is a manufacturing method of the ionizing radiation hardening-type coating-film formation body of Claim 1 characterized by the above-mentioned.

  The invention according to claim 3 is characterized in that the base material is made of a polyolefin resin, and the film thickness thereof is in the range of 20 μm to 200 μm. Ionizing radiation curable coating film formation according to claim 1 or 2 It is a manufacturing method of a body.

  According to the first and second aspects of the present invention, the ionizing radiation curable composition applied to one surface of the substrate is dried, and then the other surface side of the substrate after drying ( By irradiating the back surface side of the base material with an electron beam from the electron beam irradiation device provided on the back surface side, C on the surface of the base material on the opposite side of the base material (the side on which the ionizing radiation curable composition is applied) The —H bond is cleaved to generate a C · radical that is an active species.

  That is, due to the generation of the above active species, the ionizing radiation curable composition and the substrate are improved in adhesion through chemical bonds before the conventional ionizing radiation curable composition is cured. I can do it. As a result, an ionizing radiation curable coating film having excellent adhesion can be formed by subsequent irradiation with ionizing radiation.

  According to the invention of claim 3, the base material is made of polyolefin resin, and the film thickness is in the range of 20 μm to 200 μm. Thus, C. radicals, which are active species, can be efficiently generated.

1 is a schematic cross-sectional view of an ionizing radiation curable coating film forming body according to the present invention. Process schematic which shows one Embodiment of the manufacturing method of the coating-film formation body shown in FIG.

  Hereinafter, the present invention will be specifically described with reference to the drawings.

  FIG. 1 is a schematic cross-sectional view of an ionizing radiation curable coating film formed on one surface of a substrate according to the present invention. Moreover, FIG. 2 is process schematic which shows one Embodiment of the manufacturing method of the ionizing radiation hardening type coating-film formation body of FIG.

  In the present invention, as shown in FIGS. 1 and 2, a step of applying an ionizing radiation curable composition 2 to one surface of a substrate 1 by a coating device 3, and a diluting solvent as needed using a drying furnace 4. An ionizing radiation curable coating film forming body comprising a drying step, a step of irradiating an electron beam with the electron beam irradiation device 5 from the other surface side of the substrate 1, and a step of curing with an ionizing radiation irradiation device 6. It is a manufacturing method.

  As the base material 1 according to the present invention, sufficient adhesiveness that can withstand practical use cannot be obtained by curing the coating film by irradiation with ionizing radiation using the ionizing radiation curable composition 2 on one surface thereof. In other words, in order to improve the adhesion strength in the past, for example, the surface of the base material, on which an adhesive layer or primer layer has been indispensable, is suitable for an inactive resin base material. In particular, for example, a polyolefin resin made of polyethylene or polypropylene is preferable. The polyolefin resin may be a single resin or a laminate. Furthermore, the laminated body may be the same kind of laminated body or a different kind of laminated body, and is not particularly limited.

  The thickness of the substrate 1 is such that the electron beam irradiation device 5 irradiates the electron beam from the other surface side (back surface side) of the substrate 1 so that the substrate 1 and the cured ionizing radiation cured coating film are in close contact with each other. In order to improve the property, the thickness is preferably 20 μm to 200 μm.

  When the thickness of the base material 1 is less than 20 μm, the electron beam irradiated from the back side of the base material 1 by the electron beam irradiation device 5 reaches one surface (front side) of the base material 1, and Before the surface is sufficiently activated, the curing reaction of the ionizing radiation curable composition 2 proceeds and the adhesion strength cannot be increased.

  If the thickness of the base material 1 is greater than 200 μm, the output of a general electron beam irradiation apparatus cannot reach the surface of the base material, and the surface of the base material 1 cannot be activated.

  As the ionizing radiation curable composition 2 according to the present invention, a general ionizing radiation curable compound typified by electron beam or ultraviolet ray can be used. In addition, these ionizing radiation curable compounds can be used by adding a diluent solvent or an additive, particularly a photoinitiator or the like for curing with ultraviolet rays.

  As the ionizing radiation curable compound, for example, a monomer, oligomer, polymer or the like containing an acryloyl group as a functional group can be used. Further, by increasing the number of the functional groups, it is possible to form a crosslinked structure having a higher density.

  Next, each process according to the present invention will be described below.

  FIG. 2 is a process schematic diagram showing an embodiment of a method for producing the ionizing radiation curable molded body of FIG. 1, and individual processes and apparatuses will be described below.

  In the present invention, as shown in FIG. 2, a step of applying an ionizing radiation curable composition 2 to one surface of a substrate 1 by a coating device 3 and a step of drying a diluting solvent by a drying device 4 as required. And an ionizing radiation curable molded body comprising a step of irradiating an electron beam from the other surface side of the substrate 1 with an electron beam irradiation device 5 and a step of curing with an ionizing radiation irradiation device 6.

  A feature of the present invention is that, in the curing method, an electron beam is irradiated from the other surface side of the substrate 1 on which the ionizing radiation curable composition 2 is applied, and the one surface side (application side) of the substrate 1 is irradiated. The surface is activated to improve the adhesion between the substrate 1 and the ionizing radiation curable composition 2.

  That is, before the ionizing radiation curable composition 2 applied to one surface of the substrate 1 is irradiated with ionizing radiation from the ionizing radiation irradiation device 6 and cured, the electron beam irradiation device is applied from the other surface side of the substrate 1. 5 is irradiated with an electron beam. As a result, active species are generated on the surface of the substrate 1 on the side on which the ionizing radiation curable composition 2 is applied, and a chemical bond is generated between the substrate 1 and the ionizing radiation curable composition 2 to increase the adhesion. Then, an ionizing radiation curable coating film forming body having strong adhesion in curing by irradiation with ionizing radiation can be obtained.

  As the coating device 3 according to the present invention, various devices can be selected from lip die coaters, slot die coaters, comma coaters, blade coaters and the like according to the viscosity of the ionizing radiation curable composition. For example, when the ionizing radiation curable composition has a viscosity of 1 to 1000 mPas, a slot die coater can be selected.

  Moreover, the drying apparatus 4 according to the present invention can use hot air or an electric heater type drying apparatus generally used as a heat source, and is not particularly limited.

  The electron beam irradiation apparatus 5 according to the present invention is installed between the drying apparatus 4 and the ionizing radiation irradiation apparatus 6 at a position where the electron beam can be irradiated from the other side (non-coating side) of the substrate 1. It is characterized by that. The electron beam irradiation apparatus is not particularly limited as long as it has an output capable of transmitting active species (radicals) through a film thickness of 20 to 200 μm of the substrate 1.

  By installing the electron beam irradiation device 5 between the drying device 4 and the ionizing radiation irradiation device 6, for example, the electron beam is irradiated in a state in which the diluting solvent contained in the ionizing radiation curable composition is sufficiently evaporated. be able to. Thereby, the factor which inhibits the chemical bond of the radical which generate | occur | produced on the base-material surface and resin can be reduced, and the chemical bond of the base material 1 and an ionizing radiation-curable composition can be performed more efficiently.

  In addition, the ionizing radiation irradiation device 6 that can be used in the present invention is not particularly limited and can be a general-purpose ultraviolet irradiation device or an electron beam irradiation device. However, in the case of curing with an ultraviolet irradiation device, a photoinitiator is indispensable for the ionizing radiation curable composition.

  Examples of the present invention will be described below. In Examples, an apparatus conforming to the processing steps shown in FIG. 2 was used, and the ionizing radiation curable composition was applied, dried, irradiated with an electron beam from the back surface, and cured with ionizing radiation.

<Example 1>
Using a LLDPE (Linear Low Density Polyethylene) having a thickness of 40 μm and a width of 320 mm as the base material 1, a slot die is applied so that the coating film thickness after curing an ionizing radiation curable composition having the following composition is 10 μm The coating head of the apparatus 3 was coated at a conveyance speed of 20 m / min and dried in the drying furnace 4.

(Ionizing radiation curable composition)
UA-306H (manufactured by Kyoeisha Chemical Co., Ltd.), which is a urethane acrylate resin, has a total solid content of 60 wt. % Was adjusted. The obtained ionizing radiation curable composition had a viscosity of 10 mPas.

  Next, the dried base material 1 is subjected to an acceleration voltage of 110 KeV and a dose of 20 Mrad by an electron beam irradiation device 5 installed on the back side of the base material between the drying device 4 and the ionizing radiation irradiation device 6. Irradiated with an electron beam.

  Then, using the electron beam irradiation apparatus 5 as the ionizing radiation irradiation apparatus 6, it hardened | cured with the acceleration voltage of 140 KeV and the dose of 10 Mrad, and the ionizing irradiation ray hardening-type coating-film formation body was obtained.

<Comparative Example 1>
An ionizing radiation curable coating film forming body was obtained in the same manner as in Example except that the electron beam irradiation by the electron beam irradiation device 5 was not performed.

<Evaluation>
The adhesion strength of the ionizing radiation curable coating film formed body obtained in Example 1 and Comparative Example 1 was evaluated by a cross-cut test. In the cross-cut test, after cutting 100 squares each having a side of 1 mm within 1 cm ² from the surface of the coating film to the adhesion interface with the substrate, a general-purpose adhesive tape was adhered, and then peeled by 90 degrees. This is a method of expressing the adhesion strength by the number of squares left occasionally. The evaluation results are shown in Table 1 below.

<Comparison result>
As a result of the cross-cut test, the ionizing radiation curable coating film formed body of the present invention obtained in Example 1 maintained close adhesion between 100/100 and the substrate, and showed excellent adhesion. On the other hand, in the ionizing radiation curable coating film forming body of Comparative Example obtained in Comparative Example 1, 0/100 and all were peeled off. From the above results, according to the present invention, an ionizing radiation curable coating film forming body having excellent adhesion between the substrate and the ionizing radiation curable coating film can be obtained.

  As described above, according to the present invention, before the ionizing radiation curable composition is cured, the substrate and the ionizing radiation curable composition are adhered to each other by irradiating the base material side with the electron beam only. An ionizing radiation curable coating film forming body having various functions with improved force can be produced.

DESCRIPTION OF SYMBOLS 1 Substrate 2 Ionizing radiation curable composition 3 Coating device 4 Drying device 5 Electron beam irradiation device 6 Ionizing radiation irradiation device

Claims (3)

  A step of applying an ionizing radiation curable composition to one side of the substrate, a step of drying, a step of irradiating an electron beam from the other side of the substrate, and a side of the one side of the substrate A method for producing an ionizing radiation-curable coating film forming body, which comprises sequentially irradiating with ionizing radiation.   In the step of irradiating the electron beam from the other surface side of the base material, the electron beam irradiation apparatus for irradiating the electron beam comprises the drying furnace provided for the drying step and the ionizing radiation provided for the step of irradiating the ionizing radiation. It installed between irradiation apparatuses, The manufacturing method of the ionizing-radiation-curable coating-film formation body of Claim 1 characterized by the above-mentioned.   The method for producing an ionizing radiation curable coating film forming body according to claim 1 or 2, wherein the base material is made of a polyolefin-based resin, and the thickness thereof is in the range of 20 µm to 200 µm.

Images